Motorcycle fork extension



P C. MELLANTINE. MOTORCYCLE FORK EXTENSION.

APPHCATION' men OCT. I3. 1919.

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UNITED STATES PATENT, FIC

- mu e, riE IL AnTIivE; or} MILWAUKEE; wi cqasin;

ToaZZ whbm'it may comer 1t. I

Be it'known that I, PAUL CQMELLANTINE,

of Milwaukee, in thecounty of Milwaukee and State oflViscoh'sin,haveinvented ce'r-f tain new and useful Improvements inMotor cycle 1*orkEXtensions; and Ido 'hereby declare that the following is a full, clear, and

line 3- 3 of Fig. 2. p 1

1s a transverse"sect onal view taken enact descriptionthereof. My inventiomrelates to new and useful improvementsin thespjring fork structures of motorcycles or othe lar wheel mountings.

Although motorcycle structures when placed on the market are naturally designed to procure a maximum efliciency and comfortable riding qualities within the limitations of this type of vehicle, I have found" that an upwardcxtension ofthe forward springfork cylinders of theinotorcycle, permitting a longer stretch of the upper springs, will procure a marked increase in the riding qualities of the motorcycle by lessening vibration of the handle bars.

It is therefore the object of my invention to provide a device which may be applied as an attachment to the upper ends of the spring fork cylinders of a type of motors cycle now in general use whereby to provide an increased length of the cylinder structure above the usual cross head of the rigid portion of the motorcycle, thus permitting the use of a longer spring.

Inasmuch as the spring fork cylinders are longitudinally slotted throughout their upper portions to receive the cross-head, it is more particularly my object to provide means, operative in conjunction with an extension section threaded on the cylinder, for preventing contraction of the cylinder incidental to sudden severe stress, which would be liable to permit displacement of the extension section by release of the thread connection.

With the above and other objects and ad vantages in view, which will be apparent as the description proceeds, my invention resides in the novel features of construction, combination and arrangement of parts which will be hereinafter more particularly described and defined by the appended claims.

In the accompanying drawings:

Figure 1 is a side elevational view of the spring fork structure of a motorcycle of r vehicles having simib n te siamn Y Patented Jan. 11, 1921.. Application filedbetober 13, 1919. S e1'ia1 No. :33Q ,5I7.

Fig. 2: 'is a longitudinal sectionalview through oneof the extens1o'n' cylinder sections andg'as's'ociatedstructure, the plane of wwell kno 'wntype, showing my improved I iork'extension' device associated therewith. a cltlzen of the "United States, andresidentt' this sectionbeing indicated by the line 2-2 of Figflli r F 1g. 3 1s a transverse sectional view'on the Fig K onFl-ine'of Fig.1. c

,R'e'ierring' now more' particularly to the" accompanying drawings,-5 designates the rigidfront'fork members of a well known" typefofq motorcycle, and ,6 designates the spring fork cyli'nderswhich are pivoted at their lower endsfto the usual spring'carryinglever'members i' and whichare' provided I with the-longitudinal-slots ,8 in (311611 1111161' sides for receiving the cross head '7 project ing forwardly from the main frame of the motorcycle, springs being disposed in each cylinder 6 above and below the head 7 and the slots 8 of the cylinders 6 are extended to the upper ends thereof.

The fork structure also includes a air of cap members 9 and center rods 10 or the upper cylinder springs 11, these rods having their upper ends secured to disks 12. In the use of my attachment,-the caps 9 and disks12 are employed in positions different from the ordinary relation of parts. In said "ordinary relation of parts, the. caps 9 are threaded on the upper ends of the cylinder 6 and the disks 1-2 are disposed Within the upper ends of the cylinders and are shouldered to seat thereon.

My improved attachment comprises an extension section 13 for each cylinder 6, the diameter of this section being equal to the diameter of the cylinder and the lower portion of the section is counter-bored and threaded to receive the upper end of the cylinder 6, said counterbore forming an annular shoulder 14 in the section adjacent its lower end. The upper end of'the section 13 is threaded to receive the cylinder cap 9,and therod holding disk 12 is confined between the top of the cap and the upper end of the extension section 13, the upper spring 11 and its rod 10 being increased in length for the use of the attachment.

To prevent accidental contraction of the upper portion of the cylinder 6 by reason of.

its slot 8, a tubular bushing 15 is fitted 110 snugly in the upper portion of the cylinder 6, the wall of this bushing being of maximum thinness to permit free play of the spring therepast, and-the upper end ofthe" lieving jars and stresses imparted to the handle bar and frame structure of the motorcycle. a i

hat is claimed is: I, r 1. An extension structure for a spring fork comprising the combination-with a pair of spring fork cylinders and caps primarily adapted to be threaded on the upper ends .of said cylinders, of a pair of extension cylindersections approximately equal in diameter to said fork cylinders,said sections having their lower ends enlarged and counterbored for threadedrengagement on the upper ends of the fork cylinders; said extension sections having their upper ends threaded for reception of the caps, spring rod disks disposed between the caps and the upper ends of the extension sections, and spring extension sections and cylinders.

2. An extension structure for a spring fork comprising the combination wlth a pair of spring fork cylinders slotted longitudinally to their upper. ends, of a pair of extension cylinder sections approximately equal in diameter to said. fork cylinders, said sectionshaving" their lower portions counterboredito form shoulders therein and to providefor threaded engagement on the upper ends ofthe. fork cylinders, caps threaded 0n vthe upperends of said extension sections, spring ,rodssecured at the upper ends of said extensionsections, andibushings snugly fitted Within the upper end portions of the spring-fork cylinders,said bushings having rods depending from said-disks through the outwardly. extending flange portions on their upper ends=engagedrbetween the upper ends of the cylinders and the saidshoulders of the extension sections.

Intestirnony that I claim the foregoing I have hereuntosetmy hand at Milwaukee,

in thecounty of Milwaukee and State of Wisconsin,

PAULO. MELLANTINE. 

